Polymers composed of polymerizable monomer which has a perfluoroalkyl group in a side chain, such as a fluorine-containing alkyl ester of acrylic acid and a fluorine-containing alkyl ester of methacrylic acid, are widely known as a fluorine compound which can be cured by radiation of light, such as ultraviolet rays. As a typical example, an acrylate which has the following structure has widely been used in order to provide a substrate surface with water- and oil-repellency, stain resistance, abrasion resistance and scratch resistance.

However, recently, there is an increasing tendency with environmental concerns to regulate use of compounds which have a long-chain perfluoroalkyl group containing eight or more carbon atoms. Meanwhile, it is known that acrylic compounds having a perfluoroalkyl group with less than eight carbon atoms give a worse surface property than ones having a perfluoroalkyl group with eight or more carbon atoms do (the following Non-Patent Literature 1).
Meanwhile, photo-curable fluorine compounds are known which have a perfluoropolyether group composed of an oxygen atom which forms an ether bond and a perfluoroalkyl group containing three or less carbon atoms in series. For instance, Patent Literature 1 discloses the following acrylic compound which is derived from a hexafluoropropylene oxide oligomer.

Patent Literature 2 discloses a urethane acrylate which is a reaction product of a fluorine-containing polyether diol with 2-isocyanatoethyl methacrylate. However, the urethane acrylate has bad compatibility with photo polymerization initiators, non-fluorinated acrylates and non-fluorinated organic solvents due to the water- and oil-repellency of the fluorine-containing compounds and, therefore, can be blended with a restricted number of components and has restricted usage.
[Patent Literature 1]: Japanese Patent Application Laid-Open No. Hei-5-194322
[Patent Literature 2]: Japanese Patent Application Laid-Open No. Hei-11-349651
[Non-Patent Literature 1]: Koubunshi Ronbun-Shu Vol. 64, No. 4, pp 181-190 (April, 2007).